This K08 Mentored Research Career Award application has two broad objectives: (1) to prepare the candidate to become an independent researcher, and (2) to undertake a research project in shared decision making. The candidate is a family physician with 12 years' experience in private practice. He has unusual additional training as a law school graduate with a year's fellowship in biomedical ethics. Additional coursework in research methods, biostatistics, and psychology (and continued networking with other researchers) will provide him with a stronger understanding of the methods and topics of this challenging research area. The department will provide support and mentorship throughout the grant period. The research program itself is grounded on a new theoretical model of patient-physician decision making that emphasizes the differing characteristics of particular medical decisions. This theoretical model proposes a new approach to the question, "How can we promote shared decision making among patients (including both vulnerable and non-vulnerable populations) and their physicians?" The characteristics of medical decisions that are identified as important are the decision's potential impact, medical uncertainty, complexity, and preference sensitivity. This model underlies the proposed research program including these specific aims: (1) to develop and refine the theoretical model characterizing the appropriate allocation of decisional authority between patient and physician based on the underlying characteristics of the decision in question, (2) to develop and validate a measure of decisional authority, for use by patients and physicians, so that the theoretical model can be tested empirically, (3) to conduct a series of descriptive studies, using the measure of decisional authority, to test specific hypotheses regarding preferences for decisional authority, and (4) based on observations from Aim 3, to prepare an R01 application to extend the work beyond the limits of this grant, including work to develop and pilot test an educational tool to counsel patients and physicians to share decision making authority more appropriately. The methods used will be primarily surveys of patients and physicians, using vignettes designed to probe their preferences for how decisions should be made in specific situations; this will include different types of patients, including women, ethnic minorities, and the elderly, and different types of decisions.